The present invention relates to a rotary switch of an electronic timepiece. Recently electronic timepieces have become highly developed, and especially techniques used for realizing a quartz crystal timepiece have remarkably advanced by development of the timepiece integrated circuit (IC). In a quartz crystal timepiece, a motor is driven by frequency divided signals produced from a quartz oscillator.
Conventionally, frequencies of a quartz crystal have been determined according to a fixed frequency dividing ratio and thereby a trimmer condenser have been used as a step regulator. However, as for this method, current consumption is varied by a capacitance variation of the trimmer condenser caused by temperature variation, and therefore a current value of an oscillating circuit is set accounting for the current variation.
Attendant on recent prolongation of the lifetime of the quartz crystal timepiece, it has become necessary to decrease the current consumption of timepiece IC and if the trimmer condenser is used for regulating frequency in steps, it is necessary to set the current consumption at a high value in the normal state when the current value of the oscillating circuit is set, so that the oscillating circuit can be operated normally even if the capacity of the trimmer condenser varied. Accordingly it is difficult to decrease the current consumption. Further, in the conventional fixed frequency division, the frequency of the quartz crystal vibrator is tuned with the frequency set according to the frequency dividing ratio and the available percentage of the quartz crystal frequency having a narrow regulating range is decreased. For the quartz crystal having a narrow regulating range, the variable frequency division technique has been adopted. In this case, the switch to tune the frequency dividing ratio of the timepiece IC is necessary and the "teeth of a comb" shaped switch plated as shown in FIG. 1 was invented. In this case, however, it was necessary to tune the frequency by changing the "teeth of the comb" of the switch plate according to each of possible combinations and to complete every combination and further to prepare a number of shapes for prior assembling. When the switch plate was changed it was troublesome to remove the switch plate and also it was necessary to prepare every part for subsequent service when the timepiece was adjusted after marketing. In the manufacturing process, four pieces of the "teeth of the comb" shaped switch plates should be punched out before cutting each of the teeth and to manufacture 15 kinds of switch plates if every one of the switch plates were provided with four terminals.
Accordingly, it is an object of the present invention to provide a variable frequency dividing switch a wide adjustable range and easily adjustable by arranging more than two rotary switches having a couple of input terminals on a circuit block.